The following references are believed to represent the state of the art:
PCT Patent Publication WO2011061116 “Preventing Cloning of Receivers of Encrypted Messages”, by Dekker;
U.S. patent application Ser. No. 12/084,852 “DISK PROTECTION SYSTEM” by Mantin et al;
U.S. Patent Publication 2011/0002461 “Method and System for Electronically Securing an Electronic Biometric Device Using Physically Unclonable Functions”, by Erhart et al;
U.S. Patent Publication 2010/0272255 “Securely Field Configurable Device”, by Devedas et al;
U.S. Patent Publication 2009/0083833 “Authentication with Physical Unclonable Functions”, by Ziola et al; and
U.S. Patent Publication 2010/0177898 “Device and Method for Providing Authentication”, by Tyuls et al.